An adjustable oropharyngeal airway apparatus includes a rigid airway portion comprising a mouthpiece and a flexible airway portion frictionally engaging and slidably disposed in the mouthpiece. The notches are retained by a flange on a back plate mounted to a wall. The entry and exit seals restrict formation pressure and contaminants from entering the winding tool. The switchback roller is provided between the sorting unit and the switchback conveying path and it is rotatable in a normal direction or a reverse direction. By wavelength-multiplexing, it is possible to multiplex without a loss.